Light little nip's can be how rabbits speak to each other and to you. However, it can also be a sign of aggression.
If you have done nothing to provoke your rabbit into aggressive biting, check to make sure he/she is not scared or in pain.
"Threat biting," or bearing of teeth, occurs when your rabbit wants to show you he/she is mad, but doesn't actually want to hurt you by really biting. My rabbit Flopsy threat-bites when I'm trying to re-hutch her after an exercise period.
Chewing can mean a number of things. If your rabbit is sitting with you and starts chewing your clothing, he/she is either bored or trying to make a nest. If your rabbit is exercising and starts chewing on furniture or boxes, etc he/she is merely trying to wear down his or her teeth. This behavior is similar to a cat's scratching in order to wear down the claws.
Love bites is a form of biting that does not mean aggression. Love bites often accompany licking. When a rabbit is licking, it is trying to groom you; the soft biting is the equivalent of trying to pull knots and sticky stuff off your "fur." Rabbits do this to one another and the behavior often rubs off on owners.
Closed eyes, or partially closed eyes, occur when your rabbit is either resting or being petted in just the right spot.
It indicates happiness.
Spiked up fur, screaming, and/or other noises mean fear. If bugged eyes are accompanied by curious sniffing, straight-up ears, or your approach, it means excitement. If bugged eyes are accompanied by twitching ears and an upright position, you rabbit is being alert.
When a rabbit is uncomfortable, such as at a vet visit or after a claw trimming, he/she will sometimes indicate this emotion by allowing the inner eyelids to partially protrude and become visible. The eyes themselves will be wide.
The Mouth and Tongue
Yawning indicates sleepiness or laziness. If you ever see your rabbit open it mouth REALLY wide, bearing the teeth and stretching the face out of proportion, do not be afraid; it is merely a yawn and not a sign of aggression.
Chin rubbing is your rabbit's way of marking territory and possessions. A rabbit's scent glands are located in its chin, much like a cat's scent glands are located in its cheeks. Therefore chin rubbing is similar to a cat's cheek rubbing. If your rabbit rubs its chin on you, consider it a blessing; your rabbit has officially claimed you.
Licking is the penultimate sign of affection. It is a rabbit's way of grooming you and he/she will only groom you if he/she loves you. Licking is often prompted by lots of petting or cooing. Sometimes, a rabbit will lick you if you have some interesting taste of you hands.
Nose bumping can be either like sniffing (your rabbit wants to get a whiff of what you've been touching) or it can be a sign of affection. Sometimes a rabbit will nose-bump if it wants to be petted.
Sniffing is a sign of investigating. If your rabbit can't stop sniffing you, it usually is because you have touched another animal or the belongings of another animal.
Loud sniffing can mean one of two things. The first meaning is anger; it sometimes occurs after a claw-trimming, for example. The second meaning is exhaustion. If your rabbit has been exercising, it will sniff loudly to get more air.
Also, loud sniffing is more dignified than panting.
The Ears (note: these behaviors will be different in lop breeds)
If the ears are up and/or twitching, your rabbit is being alert and trying to hear sounds. If one ear is up and the other is down, your rabbit is still trying to listen to sounds, but is just being to lazy to use both ears. This sometimes occurs when the rabbit is resting in a sunbeam.
When your rabbit is resting, he/she will rest the ears against his/her back to indicate pleasure. The ears will be touching one another.
When the ears are flattened to the head but NOT touching to each other, this can be a sign of fright. If fright is the case, the flattened ears will be accompanied by bugged eyes, thumping, bared teeth, etc.
If the ears are pointing straight out and back, this is also a semi-relaxed position. The ears will be "rested" like this when your rabbit is exercising and pauses momentarily to lie down. The ears are not relaxed completely because your rabbit will soon be back to hopping.
Kicking/scratching is a sign of aggression. Your rabbit will usually try to kick and scratch when you are re-hutching him/her after an exercise period, or when you are trying to trim his/her claws. Kicking/scratching can also indicate fear. Try to calm your rabbit down before you are injured.
Foot-flicking, or kicking feet back and out while hopping, can indicate excitement; or, it can mean that your rabbit is "kicking your dust" off of him/herself. This occurs when you put your rabbit down after a claw trimming, or when you are setting your rabbit on the ground to exercise.
Stomping is most commonly considered a sign of fright, though I personally have also found it to mean anticipation, anger, annoyance, and even happiness or excitement. If your rabbit is thumping loudly and repeatedly while looking frightened, come to its rescue right away. Find the source of the fright and comfort your rabbit; if you allow fright-thumping to continue too long, your rabbit may die of fear. My rabbits thump in anticipation when I approach their hutch; when exercising, they thump to indicate happiness. They thump in excitement when they are first put into the exercise area. They thump in anger or annoyance when I try to re-hutch them after exercise, or after I have trimmed their claws.
Running/fast hopping is a sign of playfulness and happiness. Rabbits hop and run fast when they have a large area in which to play. If your rabbit is running turbo-speed away from something, make sure he/she is not running away in fright.
Jumping, or "binkying," is the ultimate playfulness/happiness sign when a rabbit is exercising. Binkying is different from hopping because the jump will be higher, often accompanied by a twist in the air, ear flicking, and head flipping.
Sometimes a rabbit will add a thump before a binky in order to punctuate his/her happiness.
Running back and forth, especially within a small area such as the hutch, can sometimes be a sign of fright, especially if the rabbit's eyes are bugged and the ears are flattened to the head. Comfort your rabbit if the running
goes on for longer than you feel is normal. (Sometimes your rabbit is just amusing him/herself when running like this.)
Sometimes circling an owner's feet is a sign of affection. If your rabbit is circling another rabbit or animal, watch to make sure he/she does not go from circling to mounting.
Leaping is a sign of curiosity. If your rabbit leaps up onto furniture, he/she is investigating. Be careful; rabbits sometimes miss a leap onto furniture. Discourage them from leaping too high.
Puffed out fur can mean fear or a way of keeping warm. It is very easy to distinguish between these two emotions: if it is chilly and/or your rabbit seems calm, the fur is puffed for warmth. If your rabbit is alert looking, making noise, has bugged eyes, etc the puffed fur means fear.
Pulling out fur is your rabbit's way of making a nest. This happens sometimes in winter or if your rabbit is pregnant. Sometimes, unmated females will pull out fur during pseudo (false) pregnancies.
Pulling out another rabbit's fur can be a sign of aggression. If this occurs, separate the rabbits right away and discourage the behavior.
Head butting occurs when your rabbit is trying to move something out of his/her way. If he/she is butting your hand, petting is wanted.
Throwing things (rabbits do this with their teeth) occurs when your rabbit is trying to "houseclean." They will throw objects around (in or out of the hutch) until everything seems neat to them. (NOTE: things may not necessarily seem neat to you after a rabbit has housecleaned.) Wait until your rabbit is not looking before you fix things back the way you want them. Throwing a food dish usually means that your rabbit finds the area VERY messy and needs to move even the most common objects. It does not mean that he/she is rejecting food.
Flattening of the head occurs when your rabbit wants petting (he/she will flatten the head under your hand or near your hand); when your rabbit is afraid and trying to back away from something; or when he/she is relaxing in a ball and trying to keep a little warmer and more compact.
"Head flip" is when a rabbit swishes his or her head very quickly to either the side or back. The ears will flap a bit. This movement, also known as the "half-binky" (see "binky" under the Feet category) indicates joy, playfulness, or happiness, thought not quite as much as is indicated by a full binky.
Hay shuffling, like throwing (see the Head) is also a form of housecleaning. Allow your rabbit to throw hay as it is a routine practice. If your rabbit lives indoors and hay is all over, wait until he/she is not looking before you fix it.
Otherwise your rabbit will become annoyed and rearrange it AGAIN.
Mounting of objects and other animals indicates that a rabbit is in heat. The practice of mounting should be discouraged; you may want to get your rabbit spayed if mounting becomes a problem.
Standing on the hind legs (also known as the "prairie dog" position) is a sign of curiosity. Your rabbit is trying to smell/see something higher than ground level. He/she may also be trying to estimate how high a jump is.
Washing is an important movement to watch for. Your rabbit should keep him/herself clean by washing him/herself cat style. Rabbits like to take sunbaths, especially. If one rabbit is washing another, it is a sign of love.
Sitting up is a sign that your rabbit is deciding what to do next. Maybe he/she will lie down, run or hop, start washing, etc. Sitting up and twitching the ears is a sign of alertness; your rabbit is trying to hear and see better.
The "dead bunny" position can be quite frightening. Some rabbits, when sleeping, become so relaxed that they look dead. Before you get too scared, check to see whether or not your rabbit is breathing. Most likely, he/she will be.
Laying on the back is an indication that your rabbit wants a tummy rub. Not all rabbits like tummy rubs, however, so this is not a common behavior.
Rolling dog-style occurs during exercise. Your rabbit is being playful. (Usually, only young bunnies roll over completely; as they mature this behavior becomes less common.)
The "legless rabbit" pose is when your rabbit is resting on his/her belly with all the legs tucked under him/herself.
This is often accompanied by closed eyes, flat ears, and the head being flattened so that it almost blends with the rest of the body.
When your rabbit is laying on hi/her side, with the legs stretched out completely or sometimes slightly curled in, it is also a pose of relaxing and happiness. The head should be upright, not touching the ground; if the head is lolled over to the side or touching the ground, your rabbit may be ill. A rabbit may also stretch out to catch extra sunbeams or keep cool in hot weather.
The "mid-exercise flop" occurs when your rabbit is hopping-hopping-hopping and then suddenly needs a quick rest.
He/she will spontaneously flop out on the floor, usually with the legs stretched back out into the next time zone.
Stretching is a rabbit's way of flexing its muscles after a long rest. It is often accompanied by a yawn and washing.
When stretching, a rabbit will reach far out to the front, rear in the air; then lean far forward with head in the air in order to stretch the hindquarters.
Half-stretching is when a rabbit leans very far forward while sniffing the air. The back legs are planted firmly while the front end stretches. Your rabbit is curious and is trying to sniff something just out of reach. Most likely, he/she wants to sniff before getting any closer. It is a precaution, in other words. This often occurs when you offer a new treat.
Wheezing can be either good or bad. If your rabbit is continually wheezing, it is having trouble breathing and needs a vet's attention. If your rabbit is resting, perhaps in your lap, and heaves a single big, wheezy sigh (maybe even following the sigh with shutting the eyes), he/she is expressing happiness, sleepiness, and utmost comfort.
Screaming is the ultimate sign of pain, fright, or aggression. Some rabbits will never scream, but most likely a rabbit will scream at least once in his or her lifetime. The scream sounds exactly like a little kid's scream; I can't be sure how they produce such a horrendous, loud sound. If your rabbit screams, comfort him/her immediately and stay by him/her for a few hours. Check for any dangers that provoked the screaming. Check your rabbit for injuries.
If your rabbit is injured, or if he/she still seems frightened a few hours after the scream, seek medical attention.
Purring, the motor-like sound that is most commonly associated with cats, also occurs in rabbits and means the same thing: happiness, comfort, etc. Not all rabbits purr. (Mine do not.) Others just do teeth purring (see the Teeth category.)
Honking is usually a sign of annoyance. If your rabbit is exercising and you try to pick him/her up, honking is his/her way of saying "Leave me alone! I do not wish to be returned to my hutch or cuddled! I want to HOP!"
Whining (dog-style) is a rabbit's way of expressing curiosity or annoyance. Sometimes they will make a whining noise to get attention.